Write one characteristic for change of colours chemical equation for class 7
Answers
Answer:
one characteristic for change of colour can happen when u add closine and hydrogen a green colour pigmesnt will form and it use to glow at night
Answer:
When a chemical reaction occurs, bonds in the reactants break, while new bonds form in the product. The following example explains this. Hydrogen reacts with oxygen to form water, according to the following equation:
2H2(g)+O2(g)→2H2O(g)
In this reaction, the bond between the two hydrogen atoms in the H2 molecule will break, as will the bond between the oxygen atoms in the O2 molecule. New bonds will form between the two hydrogen atoms and the single oxygen atom in the water molecule that is formed as the product.
For bonds to break, energy must be absorbed. When new bonds form, energy is released. The energy that is needed to break a bond is called the bond energy or bond dissociation energy. Bond energies are measured in units of kJ⋅mol−1.